Rotary hydraulic machine



Nov. 2, i948. E. K. BENEDEK 2,4529541 ROTARY HYDRAULIC MACHINE Filed sept. 2v, 1945 i 1s sheets-sheen rf BY @2y/JM 'f ATTORNEYS E. K. BENEDEK Nov. l2, 1948.

Filed Sept. 27, 1945 lNvENToR EL Eff /6 BEA/505K BY 6MM y WM ATT ...if mmf Nov. 2, 1948. E. K. BENEDEK Filed Sept. 27, 1945 ROTARY HYDRAULIC' MACHINE 13 Sheets-Sheet 5 BY Q//Mywyf /Q' ATTORNEYS Nov. 2, 1948. E. K. BENE-BEK 2,452,541

ROTARY HYDRAULIC MACHINE Filed Sept. 27, 1945 l 13 Sheets-Sheet 4 Q5/( w50/'SK 155776. BY iL/ML, y @zal /a ATTORNEYS Nov. 2, 1948. (E. K. BENEDEK ROTARY HYDRAULIC MACHINE 13 Sheets-Sheet. 5

Filed Sept. 27, 1945 l INVENToR y ELEM/CEENEQE/f BY/@wlffd /a ATTORNEYS Nov. 2, 1948. v E. K. BENEDEK 2,452,541

ROTARY HYDRAULIC MACHINE Filed Sept. 27, 1945 13 Sheets-Sheet G INVENToR. 2f/f CEE/vean( (fw/www Nov. 2, 1948. E. K. BENEDEK ROTARY HYDRAULIC MACHINE 13 Sheets-Sheet 7 Filed Sept. 27. 1945 l fg L Eff hf, BENEDE/c Nov. 2, 1948. E. K. BENEDEK 2,452,541'

noTARY HYDRAULIC MACHINE Filed sept. 27, 1945 13 sheets-sheet 8 EL El( /C Bax/DHC 9am/Mas Nov. 2, 1948. KE. K. BENEDEK 2,452,541

ROTARY HYDRAULIC MACHINE Filed Sept. 27, 1945 -13 Sheets-Sheet 9 www5 Nom 2, 1948. E. K. BENEDEK ROTARY HYDRAULIC MACHINE Filed sept. 27, 1945 13 Sheets-Sheet 10 INVENTO fLE/c K. BESNEDEK BY w/f/q l WW ATTORNEY 5 Nov. 2, 1948. E. K. BENEDEK ROTARY HYDRAULIC MACHINE Filed sept. 27, 1945 125 Sheets-Sheet 11 Nov. 2, 1948, E. K. BENEDEK ROTARY HYDRAULIC MACHINE ijs 'sheets-sneer 12 Filed Sep'c. 27. 1945 6 ,4 d o w M m .T L n m E. K. BENEDEK Nov. 2, 1948.

Filed Sept. 27, 1945 HW a? YK R506 50o Patented Nov. 2, 1948 UNITED STATES PATENT oFFlcE ROTARY HYDRAULIC MACHINE Elek K. Benedek, chicago, m.

Application September 27, 1945, Serial No. 618,890

Claims.

This invention relates to rotary hydraulic machines and more particularly to hydraulic pumps or motors of the kind which include a rotary barrel formed with a plurality of circumferentially deployed radial cylinders in which reciprocable pistons are mounted. Hydraulic machines of this general class are well known in the art and have been used extensively under exacting conditions of fluid pressure and rotative speed, Although numerous improvements and refinements have been contributed to the art in recent years, some difliculties remain to be eliminated or reduced in eiect. One of the diiliculties is that of maintaining proper lubrication of the parts which transmit radial thrust to the reciprocable pistons. Another undesirable characteristic of machines of this class heretofore provided has been their tendency to suck air into the cylinders resulting in noisy operati-on, and vibration frequently leading to break downs. In nearly all rotary hydraulic machines of the class referred to the driving torque is transmitted from the cylinder barrel through the radial pistons themselves. At any stage of operation one-half of the pistons are operating on suction strokes, and in prior art constructions the suction pistons must be operated without the protection of pressure film of lubricant.

An object of the invention is to overcome these difliculties by providing a hydraulic machine of the class referred to in which a iluid tight chamber filled with working or lubricating fluid houses or encloses the piston thrust-transmitting parts and those ends of the cylinders from which the pistons extend. With such a construction, the thrust-transmitting parts are sealed in a bath of lubricant which assures complete and eilicient lubrication. Furthermore the fluid in the chamber surrounds or covers the ends of the cylinders, prevents the sucking of air between the cylinders and pistons, and provides lubricant under pressure between the pistons and their respectively associated cylinders when the pistons are performing suction strokes. Thus the working fluid, which also acts as a lubricant, is maintained air-free and always available for pressure lubrication.

In accordance with the invention the foregoing stated object is achieved by providing a lubricant and working iluid containing chamber between two substantially co-rotating rotors, the chamber and the contained fluid itself rotating with the rotors. Such a construction is free from the disadvantage of hydraulically braking the rotary parts of a machine in which a bath of lubricant is maintained as a substantially sta.- tionary body in a fixed outer housing or casing.

Another object of the invention is to provide a construction of the character stated in which the fluid tight chamber is formed or provided by the cylinder barrel element, the reactance structure element, and sealing means so arranged between the barrel element and the reactance structure element as substantially to prevent leakage of fluid between the two elements but so as to permit relative movement between the elements.

Another object of the invention is to provide a construction of the kind described above and in which means are provided for delivering fluid to the sealed chamber.

Another object of the invention is to provide a construction of the kind referred to in which the body of fluid sealed in the rotating chamber minimizes the dry running and resultant excessive wearing of the suction side of the pintle and the coacting wally of the cylinder barrel bore,

- which have been characteristic of rotary hydraulic machines heretofore known.

Another object of the invention is to provide an hydraulic machine having a fluid tight chamber as described and in which the fluid pressure in the chamber is maintained substantially constant under dillerent operating conditions by means of an auxiliary source of uid acting either directly or indirectly upon the fluid in the sealed chamber.

A further object of the invention is to provide an hydraulic machine including a pintle element and a surrounding cylinder barrel element and novel and improved means for sealing the clearance between the pintle and the cylinder barrel bore on opposite sides of registering pintle and cylinder barrel parts.

Other objects will become apparent from a reading of the following description, the appended claims, and the accompanying drawings, in which:

Figures 1 to 7, inclusive, show one form of hydraulic machine embodying the invention. Figure 1 is a central, horizontal, longitudinal section taken on the line l-I of Figure 2. Figure 2 is a transverse vertical section on the line 2-2 of Figure 1. Figure 3 is a detail elevational view of a thrust-transmitting pin. Figure 4 is an end elevation of a pintle structure showing particularly a cross portion for mounting the pintle in the machine casing, and showing diagrammatically an auxiliary system for supplying fluid under pressure to certain of the parts of the main machine. Figure 5 is a view partly in eleva- 3 tion and partly in broken away section showing the pintle structure. Figure 6 is a transverse section on the line 6--6 of Figure 5. Figure 7 is an end elevation of the pintle as viewed from the right of Figure 5.

Figure 8 is a view similar to Figure 1 but showing the invention embodied in a different hydraulic machine.

Figure 9 is a view similar to Figure 1 but showing the invention embodied in a still further form of hydraulic machine.

Figures 10 and ll show the invention embodied in a further form of hydraulic machine. Figure 10 is a longitudinal vertical section on the line Ill-I0 of Figure 11. Figure 11 is a transverse section on the line II-II of Figure 10.

Figures 12, 13 and 14 illustrate the embodiment of the invention in a further form of hydraulic machine. Figure 12 is a horizontal longitudinal sectional view similar to Figure l. Figure 13 is an end elevation of a cylinder barrel incorporated in the structure shown in Figure 12. Figure 14 is a detail sectional view drawn on an enlarged scale to illustrate a resilient sealing ring.

Figure 15 is a longitudinal horizontal sectional view similar to Figure' 1 but showing the invention embodied in a still further construction.

Figure 16 is a fragmentary longitudinal horizontal sectional view of a hydraulic machine cmbodying the construction in another form.

Figure 17 is a longitudinal section of a simple pump and auxiliary pressure system and illustrates schematically basic principles of the invention.

Figure 18 is a section on the line I8I8 of Figure 17.

Figure 19 is a View similar to Figure 18 but showing relatively shiftable parts in diierent positions.

`Figure 20 is a fragmentary section of a part of a reactance member shown in Figure 12 drawn on an enlarged scale and showing a relief valve.

Figure 21 is a fragmentary longitudinal section of a simple pintle, cylinder barrel, and antifriction bearing arrangement equipped with novel sealing means in accordance with one feature of the invention.

Figure 22 is a view similar to Figure 21 but showing the sealing means in connection with bushing bearings instead of the antifriction bearings shown in Figure 21.

Figures 17, 18, and 19 show schematically a very simple pump embodying the basic principles and construction of the invention. A cylinder barrel 400 mounted to rotate on a xed pintle 40I is formed with a shaft 402 by which the barrel may be driven. A single radial cylinder 403 in the cylinder barrel 400 is adapted to communicate through a port 404 with pintle valve ports 405 and 405. A piston 401 reciprocable in the cylinder 403 has a tangential cross head 40B operable in a tangential track 409 formed in a rotary reactance member 4I0. The reactance member 4I0 is shiftable transversely of the pintle axis by suitable means (not shown) to vary the stroke oi'the piston 401. Sealing rings 4II carried by the cylinder barrel 400 have substantially uid tight sealing engagement with the end faces of the reactance member 4I0 and cooperate with the barrel and reactance member to form a rotating chamber 4 I 2. An auxiliary pump 4 I 3 supplies fluid under pressure to the chamber 4I2 through a pipe 4I4, pintle passage 4I5 and passage 4IIi in the cylinder barrel. The body of fluid` in the chamber 4I2 rotates with the rotors 400 and 4I0,

lubricates the piston and cross head, and seals the cylinder against sucking in of air. The reactance member 4I0 can be shifted laterally to an eccentric position as indicated in Figure 19 without opposition by the fluid in the chamber because a decrease in the volume of the chamber on one side of the pintle is accompanied by a corresponding increase in the volume of the chamber on the opposite side of the pintle. That is. the-total volume of the chamber is always the same. l

Referring to the commercially practical embodiment of the invention illustrated in Figures 1 to 7, inclusive, the hydraulic machine, e. g., pump or motor, is of the rotary radial piston and cylinder assembly type with the moving parts mounted in and by a casing generally designated A` equipped with an end cover I. Supported on and within the casing is apintle B around which a cylinder barrel element C is rotatable. The barrel C is formed with two sets of circumferentially deployed radial cylinders 2 which are open at their outer ends and in which are mounted plstons 3 projecting beyond the open ends of the cylinders to have thrust-transmitting connection with a reactance structure or element generally designated D. The two sets of pistons and cooperating cylinders are spaced axially from each other and the cylinders and pistons of each set are disposed in a common plane.

The pintle B comprises a cylindrical portion 4 which is snugly received by the cylinder barrel bore with just sufficient clearance between the pintle portion 4 and the barrel bore to provide for a. lubricating lm of oil. Near its left hand end as viewed in Figure 1 the pintle is formed with an enlarged centralizing boss 5 which ts into a hub 6 in the casing A. Outwardly beyond the boss 5 is a pintle cross portion 1 which is received in a recess 8 in the casing A. The cross portion l is formed with inlet and outlet ducts 9 and I0 which communicate respectively with passages II and l2 extending longitudinally through the pintle. The passages Il communicate with pintle valve ports I3 and the passages I2 communicate with pintle valve ports I4, the ports I3 and I4 opening outwardly into the clearance between the barrel bore and pintle portion 4.

The cylinder barrel is rotatably mounted by the pintle portion 4 and also by an antifriction bearing at the right hand end of the machine. As shown in Figure 1, a cap I5 secured to the right hand end of the barrel by screws I6 is integral with a shaft Il which is journaled in the casing and cap I by means of ball bearings I8, the shaft extending through a sealing device I9 carried by an end cap 20 screwed to the casing cover I. The outer races of the ball bearings I8 are held by shoulders 2| and 22 formed respec tively on the end cover I and the cap 20 and the inner races are clamped between a shoulder 23 on the shaft I1 and a nut 24. The arrangement is such that the ball bearings with their inner and outer races clamped to the cylinder barrel structure and to the casing structure respectively hold the cylinder barrel C against axial shifting on this pintle portion 4.

control the intake and discharge of fluid to and from the cylinders 2.

The reactance structure D includes an inner reactance assembly comprising end plates 26--26 secured to a central annular member or ring`21 by means of screws 28. The inner reactance assembly is journaled for rotation by means of bearings 29 supported by an outer reactance assembly including end plates 3.0 secured to a central ring 3| by means of screws 32. The outer reactance assembly 30,-3I is mounted for shifting transversely with respect to the pintle by means of pads 33 on the ring 3l which have sliding engagement with pads 34 on the casing A. The reactance structure may be shifted on this mounting by means of any suitable actuating or controlling mechanism connected to the outer reactance assembly by means of shifter rods 35.

'Ihe piston end portions projecting beyond the cylinders 2 are formed with heads 36 each of which is provided with a bore extending transversely to the piston axis and aligned with the bore in a companion piston in the other set of pistons. The arrangement is such that each pair of pistons, comprising a piston in each of the sets of pistons and cylinder assemblies, canKbe connected to the inner reactance assembly 26-21 by means of a common thrust-transmitting connection. In the form shown in Figures 1 to 7 each such pair of pistons is provided with a thrust-transmitting cross member or pin 31 mounted for rotation in the two piston head bores by means of needle bearings 38. The pins 31 are formed with three integral enlarged diameter roller portions 3.9 engaging track rings 40 mounted within the ring 21 of the inner reactance assembly.

When the reactance structure has been shifted to a position eccentric with respect to the pintle axis, rotation of the cylinder barrel, the pistons, and the pins 21 will cause the pistons toreciprocate as the pin roller portions 39 follow the eccentric tracks 40.

Pumps of this general character as thus far described and their mode of operation are well understood in the art. They frequently are operated at very highspeeds and high pressures and one of the principal difficulties which has been encountered is the elimination of noises and shocks which so frequently have been manifest under extreme operating conditions. Noises and shocks can result from imperfect cooperation of relatively moving parts and also from the sucking of air into the cylinders, particularly by way of the clearance between the cylinder walls and the outer ends of the pistons. In accordance with the present invention a substantially fluid tight rotating chamber is provided to enclose or c ontain the thrust-transmitting means or pins 31 and the parts with which they cooperate and also enclose or contain the outer ends of the cylinders. The chamber is filled with lubricant or working fluid, is cut off from communication with the interior of the stationary or main casing, and is sealed oif from communication with the ends of the 'cylinder barrel bore. In the construction shown in Figures 1 to 7 the closing of the chamber referred to is accomplished by the provision of sealing rings 4I located respectively on opposite sides of the planes containing the sets of piston and cylinder assemblies and having fluid tight engagement with both the cylinder barrel C and the end plates 26 of the inner reactance assembly. The sealing rings 4I respectively have slid- V"ing engagement with pairs of faces consisting of annular facesv 42 on the reactance end plates 26 and annular faces 43 on the cylinder barrel. The rings 4I may float transversely of the pintle axis and have peripheral contact with the roller portions 39 at the ends of the thrust-transmitting pins 31 so as to hold the roller portions 39 in operative contact with the tracks 4U and to move the pistons 3 outwardly on suction strokes when the machine is operated as a pump. Although the rings 4I can float radially and can also move circumferentially with respect to both the cylinder barrel C and the reactance plates 26, the relative radial movement is small because the ,feccentricity of the reactance structure is never great, and the relative circumferential movement is not very marked because in actual operation the rotative speed of the inner reactance assembly 26-21 will approximate that ofthe cylinder barrel.

It will be seen that the sealing rings 4| together with the inner reactance structure 26-21 and the cylinder barrel B provide a substantially uid tight rotating chamber E encompassed by but sealed 01T from communication with the casing A. In order to provide constant effective lubrication for the thrust-transmitting means located within the chamber E the chamber is maintained full of working fluid or lubricant at from fifty to one hundred pounds per square inch pressure supplied from an outside source. The fluid or lubricant not only provides effective lubrication but also seals the clearance between the pistons and the cylinder walls against the sucking in of air. Thus air is not permitted to collect in the cylinders and mix with the working fluid, and the noise and vibration heretofore caused by entrainment of air in the working fluid are eliminated.

The uid or lubricant may be introduced into the chamber E as an incident to the normal sli page of iiuid when the machine is rst placed in operation or it may be introduced by auxiliary means which is desirable particularly in connection with large machines. Such an auxiliary supply means is shown in connection with the embodiment of the invention illustrated in Figures 1 to '7. I-t includes an externally mounted gear pump 44 diagrammatically indicated in Figure 5 as being adapted to take in fluid from a reservoir 45 by means of an inlet pipe 46 and to 4discharge Huid through a pipe 41. The pipe 41 leads to a central passage 48 extending axially through the pintle B and communicating with one or more radial passages in the pintle, one of whichis shown at 49 as extending outwardly to open into a circumferential groove 50 formed in the pintle between the two `sets of piston and cylinderassemblies. The groove 50 communicates with a plurality of radial passages in the cylinder barrel, one of which is shown at 5|, extending from the cylinder barrel bore outwardly to terminate in the chamber E. `The axial pintle passage 48 may also be extended to the end of the pintle so as to discharge into a chamber 52 between the end of the pintle and the cap I5. A relief valve 53 interposed in a by-pass 54 from the discharge side -of the pump 4'4 to the reservoir 45 maintains the effective discharge pressure of the pump 44 and consequently the pressure in the chamber E at the desired value.

In use, before the main pump is placed in operation under load, the gear pump 44 is operated to deliver fluid under pressure into the chamber E, the pressure being sufficient to force air from the chamber out .through the interstices in the inner reactance structure, for example through the connections between the end plates 26 and the ring 21, and also between the rings 4I and the surfaces 42A and 43. When all of .the air has been forced out of the chamber E the latter will contain only lubricant or working fluid and the main pump can be operated under full load without danger of sucking air into the working fluid.

During rotation of the cylinder barrel fluid in the rotary chamber E is always under pressure caused by centrifugal force. Some of the fluid may leak out of the chamber duringA long operational periods. Under zero or very low working pressureT in the cylinders there would be no fluid slip past the pistons to make up for fluid which leaked out of the chamber E under the action of centrifugal force, but the auxiliary pump 44 and its appurtenances will keep the chamber full. It

' therefore is preferred to use the auxiliary fluid supply adjuncts, but if great care is obseryed in assembling the parts defining the chamber E and if the machine is not to be operated at zero or low pressures for extended periods, the slip fluid can be relied upon for maintaining the chamber E filled.

The modified construction shown in Figure 8 comprises a rotary radial piston and cylinder pump of the same general character as that illust trated in Figures 1 to 7, inclusive, the principal` difference being that in .the Figure 8 embodiment the pump is provided with four separate axially spaced sets of piston and cylinder assemblies instead of the two sets embodied in the construction shown in Figures 1 to 7. Because of the similarity of the two constructions a detailed explanation of the Figure 8 construction is not necessary. However, to assist in a consideration of Figure 8, parts of the construction therein illustrated which correspond to parts illustrated in Figures 1 to '1 are designated by similar reference characters with the exception that the reference characters applied to Figure 8 are provided with the exponent a. Thus, the casing A* shown in Figure 8 corresponds to the casing A shown in Figures 1 and 2, the sealing rings Il* shown in Figure 8 correspond to theA sealing rings 4I shown in Figure 1, and so on. Some additional detailed differences in construction may be noted. The reactance tracks 411e shown in Figure 8 are integral with .the ring 21s of the inner reactance assembly instead of being separate as shown in Figure 1. The thrust-transmitting pins 31* have integral enlarged diameter roller portions 39 at the pin centers as in the construction shown in Figures 1 and 2, but the venlarged outer or end roller portions 19l shown in Figure 8 are formed separately from the pins 31* and then applied thereto in assembly.

The operation of the construction shown in Figure 8 is similar to that described with reference to Figures 1 to '1. The chamber E* is enclosed by the barrel C, the inner reactance structure 26e-21a, and the sealing ring lle.

The form of construction illustrated in Figure 9 comprises a rotary radial piston and cylinder pump of Athe same general character as the machines illustrated in Figures 1 to 7, inclusive, and in Figure 8. It differs from the embodiment shown in Figures 1 to '1 in that the pump shown in Figure 9 is provided with four axially spaced sets of piston and cylinder assemblies; andit differs from the construction shown in Figure 8 in that the cylinder barrel is formed in two halves C"-Cb mated in alignment at 55b and held Vtogether by bolts 56h. The piston and cylinders of the two sets of piston and cylinder assemblies on each side of the barrel joint 55h are arranged in aligned pairs and are equipped with thrusttransmitting pins 31", there being one such pin for each two pistons instead of single pins for four aligned pistons as in Figure 8. Each thrusttransmitting pin has an integral enlarged roller central portion 49 and is equipped with separable enlarged roller members 39 at its ends.

Preferably an additional ring 51b is disposed inside of and in contact with the rollers 39h adjacent the medial radial plane of the cylinder barrel. This ring assists in moving the pistons outwardly during suction strokes and maintains the central roller portions 39b in engagement with the central reactance track 40".

In other respects the machine shown in Figure 9 is similar to the machine shown, in- Figures 1 r outer ends of the cylinders 2b. The chamber Eb is maintained full of liquid or working fluid so to '1, inclusive, and corresponding parts are designated by similar reference characters. Thus, the casing in Figure 9 is designated as Ab and corresponds to the casing A in Figures l and 2, the cylinders shown in Figure 9 are designated 2h and correspond to the cylinders 2 in Figures l and 2, and so on.

' In the construction shown in Figure 9 the cylinder barrel Cb-Cb, the inner reactance structure comprising the plates 26b and ring 21h, and the sealing rings Mb form the walls of an enclosed substantially fluid tight chamber Eb enclosing the thrust-transmitting parts and the as efliciently to lu'bricate the thrust-transmitting parts and to seal off the outer ends of the cylinders against the sucking in of air.'

Figures 10 and 1l illustrate the invention as being embodied in a rotary radial cylinder and piston pump of the kind employing cross heads or 'l'.-heads for thrust-transmitting connections instead of the rolling pins described with reference to the constructions shown in Figures 1 to 9, inelusive. The pump shown in Figures 10 and 11 includes a stationary casing F including plates 59 secured to the ends of the casing proper by means of screws 60. A pintle G is formed with a valve portion 6l and with a mounting portion 62 of larger diameter which is fixedly mounted in a boss 63 on the left hand end plate 59. The

pintle is formed with passages, the outer ends of which are indicated at 64 and 65. The passages 64-65 extend from the indicated outer ends longitudinally through the pintle and communicate respectively with pintle ports 66 and $1.

Mounted for rotation about the pintle G is a' cylinder barrel H formed with a plurality of circumferentially deployed radial cylinders 68 adapted to communicate with the pintle ports 66 and 61 by means of cylinder ports 69. Pistons 10 are mounted for reciprocation in the cylinders 68. Preferably the rotative mounting of the cylinder barrel is provided by means of needle bearings 1i interposed between cylinder barrel H and the piston portion 6I. In order to supplement the radial load mounting of the barrel and to hold the barrel against axial shifting, a cap 12 on the end of a shaft 13 is secured to the cylinder barrel by screws 14 and is journaled in the right hand casing end plate 59 by means of bearings 15 heldin place by an end cap 1B secured to the right hand end plate 59. The inner races pistons I are in the form of T-heads or cross heads 18 extending tangentially with respect to the pintle axis. The inner faces of the heads I8 have sliding contact with tangential faces on an inner reactance polygon ,10; .and the outer faces of the heads 18 slidably engage tangential faces on an outer reactance polygon 80. The two polygons 'I8 and 80 are positioned between reactance rings 8|-8I drawn into clamping engagement with the polygons 'I9 and 80 by means of bolts 82. 'I'he reactance assembly comprising the polygons 'I8 and 80 and the rings 8| is mounted for rotation by bearings 83 held in an outer reactance member 84 by means of snap rings 88. The outer reactance member 84 and with it the inner reactance assembly are mounted to shift transversely of the pintle axis by means of pads 86 on the outer reactance ring 84 and fixed pads 8l on the casing F. The reactance structure may be shifted as a unit by any suitable mechanism connected to the ring 84 by means of shifting rods 88.

In order to seal the thrust-transmitting heads 18 and cooperating polygon surfaces in a bath of lubricant and in order to seal the outer ends of the cylinders 68 against the sucking in of air, sealing means are provided for forming an enclosed chamber I. In this construction the chamber or enclosure is provided by the inner reactance rings 8|, the outer polygon 80, the cylinder barrel H, and a pair of sealing rings 89. The rings 88 abut radial annular surfaces 90 on the reactance ring 8| and peripherally engage the inner annular surface of the inner polygon 19. The rings 89 also have a sealing sliding fit in grooves 9| formed in the cylinder barrel H on opposite sides of the set of piston and cylinder assemblies.

In order to introduce lubricating or sealing fluid into the chamber I, fluid, which works along the pintle in the clearance between the pintle and the cylinder barrel bore is collected in a chamber at 92 at the free end of the pintle and is led past the adjacent bearings and through one or more passages 93 extending through the cylinder barrel and opening into the chamber I.

In operation, the slip fluid passing through the clearance between the pintle and the cylinder barrel bore will be conducted to the chamber I, thereby filling the chamber and maintaining it full so as to lubricate the thrust-transmitting parts effectively and also to seal the outer ends of the cylinders against the ingress of air.

In the four embodiments of the invention thus far described, the sealing rings, for example the rings 4| shown in Figure 1, preferably are relatively rigid and formed oi' a high grade alloy steel. The radial faces of the rings are highly polished as are the cooperating faces or surfaces on the cylinder barrels and inner reactance' structures. Figures 12, 13 and 14, show a modied construction which is well adapted for incorporating in pumps of a more standard design in which the surfaces of the cylinder barrel corresponding to the surfaces 43 in Figure 1, and the surfaces of the reactance corresponding to the surfaces 42 in Figure 1, are not so highly polished or machined to such close tolerances.

The machine shown in Figures 12 to 14 includes a casing 94,provided with an end plate I95 held in place by screws 90. with a valve portion 98 and with a mounting portion 99 flxedly secured in a casing boss |00. A cylinder barrel |0| is mounted for rotation about the pintle portion 88 and is connected to a shaft cap |62 by means of screws |03. 'I'he shaft or A pintle 91 is formed cap is .iournaled in ball bearings |04 carried by the casing end plate 88.

The cylinder barrel |0| is formed with a single set of circumferentially deployed radial cylinders |05 equipped with reciprocable pistons |08. Pins |01 respectively fitted to the outer ends of the pistons engage reactance tracks |08 and |08 carried by a rotatable inner reactance assembly formed of two halves ||0 secured together with bolts I. 'Ihe inner reactance element is mounted for rotation by ball bearings il! carried by an outer reactance structure comprising end plates ||3 secured to a central ring ||4 by means of screws IIB.

In operation, when the cylinder barrel is rotated and the reactance structures are set eccentrically to the pintle axis, the pistons will be reciprocated so as to draw in and expel fluid through pintle ports H8.

In order to maintain a constant bath of lubricant or fluid in contact with the reactance pins |01 and further in order to seal the outer ends of the cylinders |05 against the sucking in of air relatively resilient or soft .packing rings ||1 are interposed between the cylinder barrel and the reactance structure. The rings may be of any suitable sealing material such as soft copper wire or neoprene or carbon and should have ability to compensate for any slight irregularities of the surface which they slidingly engage. Preferably the rings ||1 are mounted in annular grooves ||0 formed on opposite radial faces of the cylinder barrel and are adapted to have sliding or rubbing engagement with annular faces ||9 on the reactance halves |I0. The cylinder barrel |09, the sealing rings I1, and the inner reactance element constituted by the halves ||0| l0 enclose or provide a fluid tight chamber |20 housing the thrusttransmitting pins |01 and the outer ends of the cylinders |05. Fluid may be introduced into the chamber |20 through a filler opening normally closed by a plug or closure I2I. The closure |2| may be formed with an extremely small hole or may be tted with a relief valve |2 |n as shown in Figure 20. The valve spring |2|b has a closing urge such as to maintain the pressure in the chamber |20 at a predetermined maximum value.

Preferably the slip of fluid along the pintle is minimized by the provision of sealing rings |22 which assist in preventing the sucking in of air at the inner ends of the cylinders. The rings |22 form the ends of a pressure lm chamber between the pintle and cylinder barrel bore and thereby confine a pressurized lm of lubricant circumferentially around the entire intervening portion of the pintle instead of allowing the lubricant to leak along the pintle to the ends of the cylinder barrel. Since fluid under pressure does not leak along the pintle to act on the end of the shaft cap |02, axial pressure thrust on the cap and on the barrel is eliminated.

The provision of sealing rings between the pintle and the wall oi' the barrel bore is advantageous generally in hydraulic machines including a cylinder barrel element and a pintle element,

one oi which elements is rotatable relatively to the other. Figure 21 shows a simple sub-assembly including a pintle 500, a cylinder barrel and antifriction bearings 502 mounting the elements 500 and 50| for rotation. one with respect to the other. In order to seal the small working clearance between the pintle and barrel bore wall, nonmetallic sealing rings 503 are mounted in seats 504 in the barrel so as to have intimate running contact with the pintle on opposite sides of the usual registering pintle and barrel ports IDB-IBI. graphite rings 502 can be tted so closely to the pintle as torprevent the loss of lubricant from the clearance between the pintle and barrel, and also to prevent the sucking of air through this clearance and into the cylinder or cylinders. The barrel-pintle sealing rings B03 are particularly advantageous when used in connection with modern axially short pintle and barrel combinations.

The construction illustrated in Figure 22 is similar to that shown in Figure 21 differing only in the use of plain bushing bearings 502* in place of the antifriction bearings 502 shown in Figure 21. The non-metallic sealing rings 503 may be used advantageously in connection with either of these or with other types of bearings.

Figure shows the invention embodied in a different form in a pump of the rotary radial piston and cylinder type similar to that shown in Figures 1 to 7. Pump parts shown in Figure 15 corresponding to parts shown .in Figures 1 to 7 are denoted by similar reference characters with the exceptior that the characters applied to the parts in Figure 15 are provided with the exponent c. Thus, the casing A shown in Figure 15 corresponds to the casing A shown in Figures 1 and 2. the pintle Bc corresponds to the pintle B, and so on. Some diilerences of a detailed nature which may be noted are that in the pump shown in Figure 15 there are three sets of circumferentially deployed radial piston and cylinder assemblies, and the thrust-transmitting pins 31e are of uniform diameter and engage directly with the thrust-transmitting tracks integral with the inner reactance ring 21.

In this embodiment of the invention the sealing of the chamber Ec is accomplished by providing sealing means integral with the cylinder barrel and the inner reactance assembly rather than by employing separate sealing rings such as the rings Il incorporated in the form shown in Figures l to 7. In the embodiment shown in Figure 15, the inner reactance end plates 26 are formed with accurately machined and polished annular surfaces I2 disposed in radial planes and respectively engaging accurately machined and polished annular surfaces 43 on the cylinder barrel Ci. The sealing means provided by the surfaces 12 and 43 cooperate with the cylinder barrel C and the inner reactance structure 28, 21 to provide the substantially fluid tight chamber E containing the thrust-transmitting means and the outer ends of the cylinders 2. In this way the thrust-transmitting means are lubricated emciently and the outer ends of the cylinders are sealed in a liquid bath so as to prevent the sucking in of air.

The embodiment o! the invention shown in Figure 16 is incorporated in a pump generally similar to that disclosed in Figures 1 to 'l'. inclusive, and corresponding parts are designated by similar reference characters with the exception that the characters applied to the parts in Figure 16 are provided with the exponent d. Thus, the casing Ad in Figure 16 corresponds to the casing A in Figures 1 and 2, the pintle Bd in Figure 16 corresponds to the pintle B in Figures 1 and 2, and so on. Some diierences in the general pump construction may be noted. In the form shown in Figure 16 the shaft I'Id is formed with a collar |24d which is drawn against a shoulder |2|i l on a cylinder barrel extension |264. Instead of journalling the shaft in the cylinder barrel as the shaft I1 of Figure 1 is journaied in the casing A,

The non-metallic, e. g., carbon or l2 the cylinder barrel extension |26d shown in Figure 16 is journaled in the casing by means of ball bearings I8d. The pumoshown in Figure 16 is provided with inner trackrrings |2'Id engaging the thrust transmitting pins 31d but these inner track rings do not seal the clearance between the cylinder barrel and the casing reactance structure as do the rings 4| in the construction shown in Figures 1 to 7. The form shown in Figure 16 includes circumferential grd'ves |28d in the cylinder barrel bore on opposite sides of the pintle ports i3d. These grooves are provided for collecting slip fluid and maintaining a constant film of lubricant in the clearance between the cylinder barrel bore and the pintle.

The pump shown in Figure 16 is similar to the pump shown in Figure 15 in that the sealing of the chamber Ed is accomplished, not by means of separate sealing rings, but by means of contacting surfaces 42d and 43.l on the inner reactance rings 'M5d and the cylinder barrel Cd respectively. These surfaces are annular, are disposed in radial planes, and are machined accurately and highly polished so as to provide a substantially fluid tight seal between the cylinder barrel and the inner reactance structure. In this way the chamber E@l is enclosed by the inner reactance assembly 28d, 21d and the cylinder barrel Cd.

In accordance with a further feature of the invention embodied in the construction shown in Figure 16, means are provided for maintaining iluid in the chamber Ed under substantially uniform pressure regardless of whether the pump is operating under load or idling. For accomplishing this the cylinder barrel is formed with at least one relief cylinder |29cl which communicates at its inner end with a passage 5|d in the cylinder barrel. A relief piston |30d mounted to reciprocate in the cylinder |29d is urged inwardly toward the pintle by a compression spring |3|d. The outer end of the spring |3|d abuts against a seat |32d formed with an aperture-|33d providing communication between the outer end of the cylinder |29d and the chamber Ed.

In operation, uid under pressure, supplied for example by a gear pump as shown in Figure 4, is introduced into the inner end of the relief cylinder |29d by way of the passages 48d and 49d, the groove 50d, and the passage 5|d. The fluid pressure acting on the inner face of the relief piston |30d will force the latter outwardly against the spring i3!d until the gear pump pressure is balanced by the force of the spring combined with the pressure of the fluid contained in the chamber Ed. If now the pump is allowed to operate idly with resultant lessening of slipping of work iluid in to the chamber Ed, the pressure of the fiuid supplied by the gear pump will act upon the piston I3!)d to force it outwardly, applying additional pressure to the iiuid in the chamber Ed. In this way fluid in the chamber is maintained under sufficient pressure to provide eilective lubrication of the thrust-transmitting parts and also to maintain the outer ends of the cylinders sealed by iluid under pressure against the sucking in of air. Figure 16 shows only one relief cylinder and piston assembly |29d, ISild.- Preferably a plurality of such assemblies is provided with the respective assemblies spaced circumferentially about the axis of the pintle.

The importance of the advantage obtained by providing the rotary fluid containing sealed chamber can be appreciated fully only when the number of lubricated parts is considered. For in- Stance, in each of the forms shown in Figures 8 and 9 respectively there are thirty-six pistons, thirty-six cylinders and thirty-six piston heads and associated thrust-transmitting members, in all more than one hundred relatively reciprocating parts. With conventional or previously known structures the coeillcients of friction of pistons performing suction strokes may be about .5 to .7 whereas with pressure lubrication afforded by the present invention the coefiicient will be reduced to not substantially more than .1. The above named great number of parts are necessitated by the novel pump structure. which reduced a large capacity pump to relatively small component parts. This could not have been achieved without the provision of more effective lubrication, than heretofore was provided by the prior art.

The constructions disclosed embody the invention in the forms now preferred, but it will be understood that changes may be made without departing from the invention as defined in the claims.

I claim:

l. -In a hydraulic machine of the character described, a rotatably mounted cylinder barrel having a plurality of radially disposed, circumferentially deployed cylinders; pistons reciprocable respectively in said cylinders and each projecting beyond an end of the associated cylinder; a reactance structure; means mounting said reactance structure to rotate about an axis eccentric to the cylinder barrel axis of rotation; thrust transmitting means interposed between said reactance structure and the piston projecting ends for effecting reciprocation of said pistons when the cylinder barrel and reactance structure rotate; and means providing a fluid tight seal between said cylinder barrel and said reactance structure; said cylinder barrel, said seal means, and said reactance structure providing a substantially fluid tight. enclosed chamber accomodating said ends of the cylinders and the piston projecting ends, said chamber being capable of retaining, without substantial leakage therefrom, a body of lubricating fluid.

2. In a hydraulic machine of the character described, a rotatably mounted cylinder barrel having a plurality of radially disposed, circumferentially deployed cylinders; pistons reciprocable respectively in said cylinders and each projecting beyond an end of the associated cylinder; a reactance structure; means mounting said reactance structure to rotate about an axis eccentric to the cylinder barrel axis of rotation; thrust transmitting means interposed between said reactance structure and the piston projecting ends for effecting reciprocation of said pistons when the cylinder barrel and reactance structure rotate; means providing a fluid tight seal between said cylinder barrel and said reactance structure; said cylinder barrel, said seal means, and said reactance structure providing av substantially uid tight enclosed chamber accomodating said ends of the cylinders and the piston vprojecting ends; and means for delivering fluid under pressure to said chamber.

8. In a hydraulic machine of the character described, a casing; a cylinder barrel mounted for rotation within said casing and having a plurality of radially disposed circumferentially deployed cylinders with open outer ends; pistons reciprocable in said cylinders and each projecting beyond the outer end of the associated cylinder; a reactance structure surrounding said cylinder barrel axis but being eccentric thereto; thrust transmitting means interposed between said reactance structure and said piston projecting ends for effecting reciprocation of said pistons when'the cylinder barrel rotates; and means providing a fluid tight seal between said cylinder barrel and said reactance structure; said cylinder barrel, said real means and said reactance structure providing a substantially fluid tight chamber enclosing the outer ends of the cylinders and the piston projecting ends, said chamber being capable of retaining, without substantial leakage therefrom, a body of lubricating iluid, said chamber being enccmpassed by said casing but being sealed off from communication with the interior of the casing.

4. In a hydraulic machine of the character described, a rotatable cylinder barrel having a plurality oi radially disposed circumferentially deployed cylinders with open outer ends; pistons reciprocable in said cylinders and each projecting beyond the outer end of the associated cylinder; a reactance structure surrounding said cylinder barrel axis but being eccentric thereto; thrust transmitting means interposed between said reactance structure and said piston projecting ends for effecting reciprocation of said pistons when the cylinder barrel rotates; and means providing a fluid tight seal between said cylinder barrel and said reactance structure; `said cylinder barrel, said seal means, and said reactance structure providing a substantially fluid tight chamber enclosing the outer ends of the cylinders and the piston projecting ends, said chamber being capable of retaining, without substantial leakage therefrom, a body of lubricating uid.

5. In a hydraulic machine of the character described. a cylinder barrel element having a plurality of radially disposed, circumferentially deployed cylinders; pistons reciprocable in said cylinders respectively and each projecting beyond an end of the associated cylinder; a substantially annular reactance element eccentric to the cylinder barrel axis; thrust transmitting means interposed between said reactance element and said piston projecting ends; means for rotating one of said elements to effect reciprocation of said pistons; and means providing a fluid tight seal between said cylinder barrel element and said reactance element; said cylinder barrel element, said seal means, and said reactance element providing a substantially fluid tight chamber enclosing the piston projecting ends.

6. In a hydraulic machine of the character described, a cylinder barrel element having a plurality of radially disposed, circumferentially deployed cylinders; pistons reciprocable in said cylinders respectively and each projecting beyond an end of the associated cylinder; a substantially annular reactance element eccentric to the cylinder barrel axis; thrust transmitting means interposed between said reactance element and said piston projecting ends; means for rotating one of said elements to effect reciprocation of `said pistons; means providing a fluid tight sea'lbev tween said cylinder barrel element and said react-` ance element; said cylinder barrel element, said seal means, and said reactance element providing a substantially fluid tight chamber enclosing the piston projecting ends; and means for delivering fluid under pressure into said chamber.

spectively in said cylinders and each projecting beyond an end of the associated cylinder; a re- 

